Hydroprocessing process for the improvement of the catalyst life

ABSTRACT

This invention relates to a hydroprocessing process for the improvement of catalyst life. Such inventive process is carried out with intermittent or discontinuous addition of a co-feed stream when hydroprocessing petroleum based feedstock or an oxygen containing feedstock. More specifically, it has been found that intermittent or discontinuous addition of the co-feed stream such as carbon monoxide, carbon dioxide, or their precursors to the hydrogen stream can reduce the long term deactivation, extend the life and increase run length of a cobalt/molybdenum hydrotreating catalyst.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional application which claims benefitunder 35 USC §119(e) to U.S. Provisional Application Ser. No. 61/360,333filed Jun. 30, 2010, entitled “HYDROPROCESSING PROCESS FOR THEIMPROVEMENT OF THE CATALYST LIFE,” which is incorporated herein in itsentirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

FIELD OF THE DISCLOSURE

This invention relates to a hydroprocessing process for the improvementof the catalyst life.

BACKGROUND OF THE DISCLOSURE

Hydroprocessing in general refers to a process of contacting a feedstockwith hydrogen at an elevated temperature and pressure using catalystwhich may vary according to the types of the feedstock, the purpose andthe condition of the process.

A classic example of hydroprocessing is the so called hydrotreatingprocess, which refers to a process of contacting a petroleum feedstockwith hydrogen at an elevated temperature and pressure usinghydrotreating catalyst to, for example, remove or lower the sulfurcontaminant from the feedstock. Hydrotreating itself can have differentpurposes and conditions such as but not limited to hydrogenation,hydrodesulfurization and hydrodenitrogenation, hydrodeoxygenation, andaromatics saturation.

In recent years, laboratory and commercial tests have demonstrated thatvegetable oils and/or animal fats can be added to a refineryhydrotreater to produce transportation fuels. However, unlike thepetroleum based feedstock, it is found that carbon monoxide and carbondioxide can be generated in the process of hydrotreating vegetable oilsand/or animal fats.

Since it is well known in the literature (Topics in Catalysis (2009)52:229-240, Bjorn Donnis et al.) that co-feeding CO or CO₂ with H₂inhibits sulfur removal. It is therefore highly desirable to 1)understand the impact of the CO and CO₂ generated from the process ofhydrotreating vegetable oils and/or animal fats oil on catalystactivity, and 2) improve the process and catalyst for hydroprocessingvegetable oils and/or animal fat oil including extending the life of thehydroprocessing catalyst.

BRIEF SUMMARY OF THE DISCLOSURE

This invention relates to a hydroprocessing process for the improvementof the catalyst life. Such inventive process is carried out withintermittent or discontinuous addition of a co-feed stream whenhydroprocessing a petroleum based feedstock or an oxygen containingfeedstock. More specifically, it has been found that intermittent ordiscontinuous addition of the co-feed stream such as carbon monoxide,carbon dioxide, or their precursors to the hydrogen stream can reducethe long term deactivation, extend the life and increase run length of acobalt/molybdenum hydrotreating catalyst.

One embodiment of the invention relates to a process comprising thesteps of a) providing a petroleum based hydrocarbon feedstock; b)providing a hydroprocessing catalyst; c) providing a co-feed stream; andd) contacting the petroleum based hydrocarbon feedstock with thehydroprocessing catalyst under hydroprocessing conditions withintermittent or discontinuous addition of the co-feed stream. Theco-feed stream refers to CO, CO₂, or their precursor.

Another embodiment of the invention relates to a process comprising thesteps of a) providing an oxygen containing feedstock; b) providing ahydroprocessing catalyst; c) providing a co-feed stream; d) contactingthe oxygen containing feedstock with the hydroprocessing catalyst underhydroprocessing conditions with intermittent or discontinuous additionof the co-feed stream. The co-feed stream refers to CO, CO₂, or theirprecursor.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention and benefitsthereof may be acquired by referring to the follow description taken inconjunction with the accompanying drawings in which:

FIG. 1 is a graph showing the effect of CO, CO₂ on Product Sulfur.

DETAILED DESCRIPTION OF THE DISCLOSURE

This invention relates to a hydroprocessing process for the improvementof the catalyst life. Such inventive process is carried out withintermittent or discontinuous addition of a co-feed stream whenhydroprocessing a petroleum based feedstock or an oxygen containingfeedstock. More specifically, it has been found that intermittent ordiscontinuous addition of the co-feed stream such as carbon monoxide,carbon dioxide, or their precursors to the hydrogen stream can reducethe long term deactivation, extend the life and increase run length of acobalt/molybdenum hydrotreating catalyst.

Turning now to the detailed description of the preferred arrangement orarrangements of the present invention, it should be understood that theinventive features and concepts may be manifested in other arrangementsand that the scope of the invention is not limited to the embodimentsdescribed or illustrated. The scope of the invention is intended only tobe limited by the scope of the claims that follow.

According to the first embodiment of the current invention, there isprovided a process for hydroprocessing a petroleum based hydrocarbonfeedstock to make fuel product by contacting the petroleum basedhydrocarbon with hydroprocessing catalyst under hydroprocessingconditions with intermittent or discontinuous addition of a co-feedstream. The co-feed stream refers to CO, CO₂, or their precursor.

According to the 2^(nd) embodiment of the current invention, there isprovided a process for hydroprocessing an oxygen containing feedstock tomake fuel product by contacting the oxygen containing feedstock withhydroprocessing catalyst under hydroprocessing conditions withintermittent or discontinuous addition of a co-feed stream. The co-feedstream refers to CO, CO₂, or their precursor.

The term “hydroprocessing” in general refers to a process for contactinga feedstock with a treating gas at an elevated temperature and pressureusing catalyst which may vary according to the types of the feedstock,the purpose and the condition of the process. Hydroprocessing conditionsinclude temperatures in the range from about 250 to about 800° F. andpressure in the range from about 100 psig to about 2500 psig.

Hydroprocessing in general is carried out in the presence of acatalytically effective amount of hydroprocessing catalyst containingmetals. Such catalysts generally involve a carrier such as a refractoryinorganic oxide having deposited thereon a metal that may be selectedfrom Groups 3-10 of the Periodic Table based on the IUPAC format havingGroups 1-18. According to one embodiment of the invention, the metal isselected from Groups 3-10. According to another embodiment, the metal isselected from Groups 6 and 8-10 including but not limited to Mo, W, Ni,Co, and Ru. Unsupported hydroprocessing catalysts can also be used inhydroprocessing process.

Commercial hydroprocessing catalysts are readily available from avariety of sources including ALBEMARLE, ADVANCED REFINING TECHNOLOGIES(ART), PGM CATALYSTS & CHEMICALS, AMERICAN ELEMENTS, EURECAT, FISCHER,HALDOR TOPSOE, HEADWATER, SIGMA, and other chemical suppliers. Catalystsmay be microsized, nanosized, fluidized or other catalyst formsdependent upon the reactor size, shape and conditions under which thereaction is run.

The term hydroprocessing includes but not limited to hydrotreating,hydrocracking, and any process in which a hydrocarbon feed is reactedwith a treating gas (e.g. hydrogen for hydrotreating process).

Hydrotreating process refers to a process of contacting a petroleumfeedstock or oxygen containing feedstock with hydrogen at an elevatedtemperature and pressure using hydrotreating catalyst to, for example,remove or lower the sulfur contaminant from the feedstock. Hydrotreatingitself can have different purposes and conditions such as hydrogenation,and hydrodesulfurization (HDS), hydrodenitrogenation (HDN),hydrodeoxygenation (HDO) and aromatics saturation.

Hydrotreating process conditions include temperatures in the range fromabout 250 to about 800° F., pressure in the range from about 100 psig toabout 2500 psig. The hydrogen treat gas rate in the range of about 100to 10,000 scf/B (standard cubic feed gas per barrel of liquid) and aliquid hourly space velocity in the range of about 0.1 to about 10hr.⁻¹.

The hydrotreating process in general is carried out in the presence ofcatalyst containing at least one metal from Groups 6, 8, 9 and 10 of thePeriodic Table, based on the IUPAC format having Groups 1-18. In oneembodiment, such catalysts include Co, Mo, Ni, W, and Ru. In the case ofhydrogenation, hydrodesulfurization (HDS), hydrodenitrogenation (HDN),hydrodeoxygenation (HDO), and aromatics saturation, such catalystscontain Co, Mo, Ni, W, and mixtures thereof such as Co/Mo, Ni/Mo, Ni/Wand Ni/Mo/W. These catalysts are usually supported on a refractoryinorganic oxide support such as alumina, silica, silica-alumina and thelike. Unsupported hydroprocessing catalysts can also be used inhydroprocessing processes.

Another example of hydroprocessing is the so called hydrocrackingprocess, which refers to a process of contacting a petroleum based oroxygen containing feedstock with hydrogen at an elevated temperature andpressure using hydrocracking catalyst, for example, NiW on Al2O3-SiO2.Hydrocracking can include several reactions such as hydrocracking,hydrodesulfurization (HDS), hydrodenitrogenation (HDN),hydrodeoxygenation (HDO) and aromatics saturation.

Hydrocracking process conditions include temperatures in the range fromabout 500 to about 900° F., pressures in the range from about 100 toabout 2500 psig, hydrogen treat gas rate in the range of about 100 to10,000 scf/B and a liquid hourly space velocity in the range of about0.1 to about 10 hr⁻¹.

Hydrocracking catalysts include an acid support serving as crackingcomponent and a hydrogenation component. The cracking component may beamorphous or crystalline. Amorphous cracking catalysts includesilica-alumina. Crystalline cracking catalysts are molecular sievesincluding aluminosilicates such as zeolites and aluminophosphates suchas SAPOs. Examples of zeolites as cracking catalysts include Y zeolite,beta zeolite and ZSM-5. Examples of SAPOs as cracking catalysts includeSAPO-5, SAPO-34. Hydrogenation components include Group 6 or Group 8-10metals or oxides include but not limited to one or more of molybdenum,tungsten, cobalt, nickel, or the oxides thereof.

Referring to the 1st embodiment of the invention, the petroleum basedhydrocarbon useful for the invention includes but not limited to a fullrange of feeds from paraffins and light virgin naphthas to whole crudesand include both natural and synthetic feeds. Boiling points for feedsmay range from about 100 to greater than about 1000° F. Examples of suchfeeds include C5+ paraffins, naphthas, kerosene, gasoline, heating oils,jet fuels, diesel, cycle oils, catalytically cracked light and heavy gasoils, hydrotreated gas oil, light flash distillate, vacuum gas oil,light gas oil, straight run gas oil, coker gas oil, synthetic gas oil,deasphalted oils, foots oil, slack waxes, waxes obtained from aFischer-Tropsch synthesis process, long and short residues, andsyncrudes, optionally originating from tar sand, shale oils, residueupgrading processes and etc,

Referring to the 2^(nd) embodiments of the invention, the oxygencontaining feedstock refers to any feed molecules containing oxygenatoms. The oxygen containing feedstock useful for the invention includesbut not limited to vegetable oil, animal fats, algae oil, glycols,polyols, sugar alcohols, biomass, and organic compounds containingfunctional groups that can be reduced (hydrogenated) such as aldehydes,ketones, esters, amides and carboxylic acids. In general, any oxygencontaining feedstock may undergo the reactions, such as decarbonylationand decarboxylation to produce carbon monoxide and carbon dioxide,respectively, while undergoing a hydroprocessing process.

Refer to the 1^(st) and 2^(nd) embodiments of the invention, the co-feedstream useful for the current invention includes but not limited to CO,CO₂, or their precursor. A CO or CO₂ precursor is a compound whichreleases CO or CO₂ under hydroprocessing conditions. Examples of such COor CO₂ generating precursors include carboxylic acids, carbonates,formaldehyde, glyoxal, and carbonyls. Since the oxygen containingfeedstock may undergo reactions during hydroprocessing, such asdecarbonylation and decarboxylation to produce carbon monoxide andcarbon dioxide, respectively, therefore, any oxygen containingfeedstocks, such as vegetable oil, animal fats, algae oil, glycols,polyols, sugar alcohols can also serve as CO and CO₂ precursors.

Further referring to the 1^(st) and 2^(nd) embodiment of the invention,the feedstock may be contacted with a hydroprocessing catalyst underhydroprocessing conditions including treating gas such as hydrogen. Aco-feed stream may be added to the treating gas or directly to thehydroprocessing reactor. Any hydroprocessing reactor known to the peopleskilled in the art may be used for this invention. The co-feed streammay be added in the matter of, but not limited to, intermittent,discontinuous, pulsed, staged, or non-steady. In one embodiment suchintermittent or discontinuous addition of the co-feed stream may occuras follows: co-feed is added for 1 to 10 days, followed by 1 day to 50weeks without co-feed during the hydroprocessing process. In anotherembodiment such intermittent or discontinuous addition of the co-feedstream may occur for 1 to 5 days followed by 1 day to 25 weeks withoutco-feed. In yet another embodiment such intermittent or discontinuousaddition of the co-feed stream may occur for 2 or 3 days followed by 4days to 10 weeks without co-feed.

The following examples of certain embodiments of the invention aregiven. Each example is provided by way of explanation of the invention,one of many embodiments of the invention, and the following examplesshould not be read to limit, or define, the scope of the invention.

Example 1

Laboratory and commercial tests have demonstrated that vegetable oilsand/or animal fats can be added to a refinery hydrotreater to producetransportation fuels. Since carbon monoxide and carbon dioxide can begenerated from oxygen containing feedstocks such as animal fat andvegetable oils in this hydrotreating process, experiments were run tostudy the effects that CO and CO₂ would have on the performance of acommercially available cobalt/molybdenum catalyst. The evaluationconsisted of a seven month test run on a laboratory hydrotreater using adiesel feed with 2000 ppm sulfur. The hydrotreating conditions were setto achieve a product sulfur level of about 10 ppm. The experiment wascarried out at 642 F, 1400 scf/B, 600 psig, 1.0 hr⁻¹, Co/Mo catalyst anddiesel feed (sulfur level of ˜2000 ppm) as base case. At theseconditions, product sulfur level was about 10 ppm at the beginning ofthe run. During the 7 month test, CO or CO₂ was co-fed with H2intermittently. The catalyst performance was evaluated based on theproduct sulfur level.

The result is shown in FIG. 1. Using a commercially availablecobalt/molybdenum catalyst and a diesel feed with 2000 ppm sulfur, theproduct sulfur level was about 10 ppm. Not surprisingly and consistentwith results reported in the literature, when CO and/or CO₂ were co-fedwith H₂, the product sulfur level increased to a range from 30 to 90ppm. However, as shown in FIG. 1, when the carbon oxides were removedfrom the feed, the product sulfur level returned to 10 ppm. Moresignificantly is that the product sulfur level remained at about 10 ppmat base case conditions over this testing period while either CO or CO₂was co-fed intermittently. There was no catalyst deactivation observed.

In other words, it was found that the intermittent feeding with eitherCO or CO₂ results in reduced catalyst deactivation and an increase inexpected run length which is unexpected. The current invention suggeststhat periodically adding CO and/or CO₂ increases the useful life of thecatalyst over what would be predicted using well establishedhydrotreating reaction models.

In closing, it should be noted that the discussion of any reference isnot an admission that it is prior art to the present invention,especially any reference that may have a publication date after thepriority date of this application. At the same time, each and everyclaim below is hereby incorporated into this detailed description orspecification as an additional embodiment of the present invention.

Although the systems and processes described herein have been describedin detail, it should be understood that various changes, substitutions,and alterations can be made without departing from the spirit and scopeof the invention as defined by the following claims. Those skilled inthe art may be able to study the preferred embodiments and identifyother ways to practice the invention that are not exactly as describedherein. It is the intent of the inventors that variations andequivalents of the invention are within the scope of the claims whilethe description, abstract and drawings are not to be used to limit thescope of the invention. The invention is specifically intended to be asbroad as the claims below and their equivalents.

1. A process comprising a) providing a feedstock selected from apetroleum based hydrocarbon feedstock or an oxygen containing feedstock;b) providing a hydroprocessing catalyst; c) providing a co-feed stream;and d) contacting said feedstock with said hydroprocessing catalystunder a hydroprocessing condition with an intermittent or adiscontinuous addition of said co-feed stream.
 2. The process of claim 1wherein said petroleum based hydrocarbon feedstock is selected from agroup consisting of C5+ paraffins, naphthas, kerosene, gasoline, heatingoils, jet fuels, diesel, cycle oils, catalytically cracked light andheavy gas oils, hydrotreated gas oil, light flash distillate, vacuum gasoil, light gas oil, straight run gas oil, coker gas oil, synthetic gasoil, deasphalted oils, foots oil, slack waxes, waxes obtained from aFischer-Tropsch synthesis process, long and short residues, syncrudes,optionally originating from tar sand, shale oils, residue upgradingprocesses, and any mixture thereof
 3. The process of claim 1 whereinsaid oxygen containing feedstock is any feed molecules containing oxygenatoms.
 4. The process of claim 1 wherein said oxygen containingfeedstock is selected from a group consisting of vegetable oil, animalfat, algae oil, glycols, polyols, sugar alcohols, biomass, organiccompounds, and any mixture thereof
 5. The process of claim 4 whereinsaid biomass or organic compound contains functional groups which can bereduced or hydrogenated.
 6. The process of claim 1 wherein saidintermittent or discontinuous addition of said co-feed stream occurs for1 to 10 days followed by 1 day to 50 weeks without co-feed.
 7. Theprocess of claim 1 wherein said intermittent or discontinuous additionof said co-feed stream occurs for 2 to 3 days followed by 4 to 10 weekswithout co-feed.
 8. The process of claim 1 wherein said co-feed streamis CO, CO₂, or their precursor.
 9. The process of claim 8 wherein saidprecursor is a compound which releases CO or CO₂ under saidhydroprocessing condition.
 10. The process of claim 8 wherein saidprecursor is selected from the group consisting of carboxylic acids,carbonates, formaldehyde, glyoxalin, carbonyls, vegetable oil, animalfat, algae oil, glycols, polyols, sugar alcohols, and any mixturethereof.
 11. The process of claim 1 wherein said hydroprocessingcatalyst is a metal-containing hydroprocessing catalyst.
 12. The processof claim 11 wherein said metal is selected from Groups 3-10 of thePeriodic Table.
 13. The process of claim 11 wherein said metal isselected from a group consisting of Mo, W, Ni, Co, Ru, and mixturethereof.
 14. The process of claim 1 wherein said hydroprocessingcatalyst is supported on an inorganic oxide support.
 15. The process ofclaims 1 wherein said hydroprocessing condition comprises a temperaturein the range from about 250 to about 800° F., a pressure in the rangefrom about 100 to 2500 psig.
 16. The process of claims 1 wherein saidhydroprocessing process is a hydrotreating process carried out by ahydrotreating catalyst under a hydrotreating condition.
 17. The processof claim 16 wherein said hydrotreating condition comprises a temperaturein the range from about 250 to about 800° F., and a pressure in therange from about 100 to 2500 psig.
 18. The process of claim 16, whereinsaid hydrotreating catalyst is selected from a group consisting of Co,Mo, Ni, W, and mixtures thereof
 19. The process of claim 16, whereinsaid hydrotreating process is hydrogenation, hydrodesulphurization,hydrodenitrogenation, hydrodeoxygenation or aromatics saturation. 20.The process of claim 1 wherein said hydroprocessing process is ahydrocracking process carried out by a hydrocracking catalyst under ahydrocracking condition.
 21. The process of claim 20 wherein saidhydrocracking catalyst is selected from a group consisting of Co, Mo,Ni, W and any combination thereof
 22. The process of claim 20 whereinsaid hydrocracking conditions comprises a temperature in the range fromabout 500 to about 900° F., and a pressure in the range from about 100to 2500 psig.